What is the purpose of the attemperator?

• A. It controls superheated steam temperature by injecting small amounts of boiler feed water into the steam header
• B. It vents steam to atmosphere
• C. It adds chemicals to water
• D. It increases boiler pressure

Answer: (A)

An attemperator is used to control the temperature of steam, especially when the steam is hotter than needed. It does this by injecting small amounts of boiler feed water into the steam header, which mixes with the steam and absorbs heat, lowering the steam temperature to the desired level. This helps protect turbines and downstream equipment from overheating and keeps the process conditions stable as load or steam demand changes. It is not about venting steam, adding chemicals to water, or increasing boiler pressure, which is why the injection of boiler feed water to cool the steam is the correct purpose.